CVE-2026-35054 XenForo Stored Cross-Site Scripting via BB Code Rendering
Attackers can inject malicious scripts via BB code in XenForo, leading to stored XSS and potential account takeover when viewed by other users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-35054?
CVE-2026-35054 is a medium-severity cross-site scripting vulnerability in XenForo, published on 1 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
XenForo before 2.3.9 is vulnerable to stored cross-site scripting (XSS) related to BB code rendering. An attacker can inject malicious scripts through BB code that are stored and executed when other users view the content.
Weakness: CWE-79
Which versions are affected by CVE-2026-35054?
It affects 1 product.
Products include Xenforo Xenforo.
How do I fix CVE-2026-35054?
No fix has been published for CVE-2026-35054 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-35054 being exploited?
There is no known exploitation of CVE-2026-35054 in the wild and no public exploit code.
Other vulnerabilities in XenForo
- CVE-2025-71279 XenForo Passkey Security Bypass
- CVE-2026-73309 XenForo < 2.3.13 Authentication Bypass via OAuth2 Token Endpoint
- CVE-2026-73311 XenForo < 2.3.13 OAuth2 Authorization Code Reuse
- CVE-2026-73312 XenForo < 2.3.13 Refresh Token Replay via Expired Access Token
- CVE-2024-38457 Xenforo before 2.2.16 allows CSRF.
Sources
Also known as GHSA-2ch2-j7qp-pqm3.